Motor vehicle seat

ABSTRACT

A motor vehicle seat includes at least one adjusting device, by means of which the position of a seat part can be adjusted against its weight and/or against the weight of a vehicle occupant sitting on the seat, and at least one spring element, which acts under preload on a kinematic chain of at least one adjusting device in order to reduce the backlash thereof, the kinematic chain transmitting the adjusting force. The spring element is arranged such that, on an adjustment of the seat part against the weight, the spring element is released, in order to supply the kinematic chain with spring energy, and tensioned on an adjustment of the seat part in the weight direction.

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application is a National Phase Patent Application ofInternational Application Number PCT/DE02/03410, filed on Sep. 9, 2002,which claims priority of German Patent Application Number 101 45 843.6,Filed on Sep. 10, 2001.

BACKGROUND OF THE INVENTION

[0002] A motor vehicle seat is disclosed in DE 198 45 772 A1 having atleast two adjusting devices for adjusting the seat and/or parts of theseat whereby the adjusting device has means for compensating for anypossible backlash in the adjusting device. The means for compensatingfor the backlash comprise a pretensioned elastic element which isarranged so that the force generated by the elastic element acts on thegearing of at least two adjusting devices, the force generatedpreferably having components parallel to the direction of each adjustingmovement produced by the individual adjusting devices. In this manner itis possible to compensate for any possible backlash in two or moreadjusting devices with only one elastic element.

[0003] According to the disclosure of DE 198 45 772 A1, it is alsopossible for a spring element to compensate the backlash of severaladjusting devices in a motor vehicle seat.

SUMMARY OF THE INVENTION

[0004] A motor vehicle seat according to the present invention comprisesin one embodiment at least one adjusting device with which a part of theseat can be adjusted in position against its own weight and/or againstthe weight of an occupant of the seat. The seat also comprises at leasta spring element to reduce backlash. The spring element is pretensionedon a kinematic chain of the at least one adjusting device wherein thekinematic chain transfers the adjusting force.

[0005] The adjusting device may comprise a device for adjusting the seatheight, or a device for adjusting the backrest rake of a vehicle seat.The kinematic chain serves to transfer the adjusting force from a driveof the relevant adjusting device to the seat part which is to beadjusted (which in exemplary embodiments include a vertically adjustableseat frame or an incline-adjustable seat back) and can be formed in oneembodiment as a lever assembly.

[0006] In one embodiment of the present invention, the spring elementserving to compensate for the backlash is arranged so that duringadjustment of the seat part, it relaxes against the weight so thatspring energy is introduced into the kinematic chain. During adjustmentof the seat part in the direction of the weight the spring element istensioned.

[0007] This arrangement of the spring element has the advantage that thespring element assists the adjusting movement opposite the loadingdirection while counteracting an adjusting movement of the seat part inthe direction of the force of the weight. The spring element equalizesadjusting forces required for adjusting a seat part against the weightwith those required for adjusting a seat part with the weight. Inparticular, the situation is avoided wherein the adjusting forcerequired for adjusting a seat part against the weight is substantiallylarger than the adjusting force required for adjusting a seat part inthe loading direction.

[0008] In a preferred embodiment, the spring element exerts a force witha component in the loading direction on a force engagement point whichis associated with the seat part which is to be adjusted. In alternativeembodiments, the force engagement point may be located either on theseat part itself or on a component part which during actuating of theadjusting device can move together with the seat part. The forceengagement point of the spring element which is to be associated withthe seat part to be adjusted is arranged so that it is moved duringdisplacement of the seat part opposite the loading direction so that thespring element is relaxed.

[0009] This behaviour of the spring element which is initiallycontradictory can be reached with a spring element which serves toreduce the backlash of an adjusting device for the height of a seatpart. The spring element is tensioned between its two force engagementpoints and inclined to the loading direction such that it relaxes whenthe seat part is lifted as a result of the superimposed longitudinalmovement of the seat part in the seat longitudinal direction. Thebacklash which causes, during adjustment of the height, a longitudinalmovement of the seat part in the seat longitudinal directionsuperimposed thereon (as is conventional in the case of seat heightadjusting devices based on a parallelogram kinematic principle).

[0010] With a spring element which serves to reduce the backlash of anadjusting device for the incline of a seat part mounted to pivot aboutan axis whereby the adjustable seat part forms in relation to thepivotal axis a first lever arm (as is usual in adjusting devices for thebackrest incline), the force engagement point of the spring elementassociated with the seat part is arranged outside of the first lever armon a second lever arm which is formed in one embodiment through aprojection of the seat part.

[0011] In one embodiment, the spring element can be formed as a tensionspring the force engagement points or which move closer together whenadjusting the corresponding seat part opposite the loading direction andmove further apart when adjusting the seat part in the loadingdirection.

[0012] In an alternative embodiment, the spring element is a compressionspring arranged so that its force engagement points move away from eachother during adjustment of the corresponding seat part opposite theloading direction and move closer together during adjustment in theloading direction.

[0013] The spring element can be of different spring types adapting tothe conditions of the relevant adjusting device. In various embodimentsthe spring element is a linear spring, a torsion spring or a coilspring.

[0014] In a preferred embodiment of the invention, all members of thekinematic chain of the adjusting device lie between the force engagementpoints of the spring element so that the spring element causes areduction in the play of the overall adjusting device.

[0015] A force engagement point of the spring element preferably liesoutside of the kinematic chain of the adjusting device, moreparticularly on a part which during actuation of the adjusting devicedoes not changes its position relative to the vehicle body. In oneembodiment, this part may be a part of the base group of the seat. In afurther embodiment it may be the top rail of a rail longitudinal guide.

[0016] The other force engagement point of the spring is provided on apart which during actuation of the adjusting device does change itsposition (together with the seat part which is to be adjusted), forexample on a part of the kinematic chain of the adjusting device. Thepart which changes its position can thereby be moved throughoutactuation of the adjusting device relative to the seat part. It issolely decisive that the corresponding part is moved along automaticallyduring movement of the seat part which is to be adjusted.

[0017] In one embodiment, the movable force engagement point is mountedon a pivotal lever arm or a gearing element of the kinematic chain.

[0018] In an alternative embodiment of the invention, one forceengagement point of the spring element is provided on the seat partwhich is to be adjusted and the other force engagement point of thespring element is provided on a link of the kinematic chain.

[0019] In another alternative embodiment, a force engagement point ofthe spring element associated with the seat part which is to be adjustedis provided on an additional gearing element which is mounted outside ofthe kinematic chain of the seat adjusting device. This force engagementpoint acts on one element of the kinematic chain, preferably a gearingelement. The phrase “mounted outside of the kinematic chain” means inthis context that the additional gearing element interacts with thekinematic chain only as a result of the action of the spring element,and that the kinematic chain could also transfer fully functioningadjusting forces without the additional gearing element.

[0020] The additional gearing element preferably acts under thepretensioning force of the spring element on the said element of thekinematic chain so as to assist movement of the element of the kinematicchain which leads to an adjustment of the seat part opposite the loadingdirection. Spring energy may then be fed into the kinematic chain.Conversely, in this case the additional gearing element counteracts anadjustment of the corresponding seat part in the loading direction as aresult of the pretensioning force of the spring element.

[0021] With this arrangement, the spring element can serve together withthe additional gearing element to remove the backlash from the gearingelements of the adjusting devices by the additional gearing elementacting on a gearing element of the kinematic chain. By removing thebacklash, this additional gearing element is pressed against the gearingelement of the kinematic chain.

[0022] In one embodiment of the present invention, a gear wheel drivenby the drive of the adjusting device engages a gearing element mountedin the kinematic chain whereby an additional toothed gearing element isprovided the teeth of which coincide with the gearing element mounted inthe kinematic chain. The gearing element mounted in the kinematic chainand the additional gearing element can thereby be formed in oneembodiment as pivotally mounted toothed segments. The additional gearingelement can be mounted to pivot freely on the axis of the gearingelement mounted in the kinematic chain. The force engagement point ofthe spring element on the additional gearing element is spaced from thisaxis.

[0023] It is understood that the use of an additional gearing elementfor removing the backlash from the gearing is independently possible forany type of gearing, more particularly for a toothed wheel gearing.

[0024] Further features and advantages of the invention will now beexplained with reference to the embodiments illustrated in the followingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a diagrammatic view of a vertically adjustable vehicleseat with a spring element for reducing the backlash in the adjustingdevice for the seat height which engages with one end on the heightadjustable seat part;

[0026]FIG. 2 shows a modification of the embodiment of FIG. 1 in whichthe spring element engages with one end on an adjusting lever of theadjusting device for the seat height;

[0027]FIG. 3 shows a further modification of the embodiment of FIG. 1wherein the spring element engages by one end on an additional gearingelement which does not serve for transferring adjusting forces on theseat part which is to be adjusted;

[0028]FIG. 4 is an enlarged view of a detail of the assembly of FIG. 3;

[0029]FIG. 5 shows a modification of the embodiment of FIG. 4;

[0030]FIG. 6 depicts a diagrammatic view of an incline-adjustable seatback with a spring element for reducing the backlash in the adjustingdevice for the backrest rake;

[0031]FIG. 7 shows a modification of the embodiment of FIG. 6 in whichthe spring element engages an additional gearing element which does notserve for transferring adjusting forces onto the backrest.

DETAILED DESCRIPTION OF THE INVENTION

[0032]FIG. 1 shows a side view of a seat frame 1 comprising aheight-adjustable seat support 10 as well as a backrest 20 pivotallyattached thereon.

[0033] A known parallelogram kinematic system exists for adjusting theheight of the seat support 10 in which a front adjustment lever 11 and arear adjustment lever 12 are attached on each side of the support 10 topivot about the axes 11 a and 12 a, respectively. The adjustment levers11 and 12 are each mounted at one end to pivot about the axes 11 b and12 b respectively on a structural assembly on the vehicle floor side. Inone embodiment, this structural assembly may comprise the top rail of alongitudinal rail guide. With an adjusting device of this kind, anychange in the seat height h which is triggered by pivoting theadjustment levers 11 and 12 leads to a corresponding shift of the seatsupport 10 in the seat longitudinal direction L (corresponding to thevehicle longitudinal axis in a motor vehicle). In more precise terms,any increase in the seat height h leads to the seat support 10 shiftingforwards and any reduction in the seat height h leads to the seatsupport 10 shifting back (in relation to the forward drive direction ofthe vehicle).

[0034] In order to reduce the play in the adjustment device for theheight of the seat support 10 and thus of the seat overall, a springelement 5 is provided comprising a linear tension spring fixed at oneend at a first force engagement point 51 to a floor-side structuralassembly of the vehicle (e.g. to the top rail of a longitudinal railguide a) and at its other upper end at a second force engagement point52 to the seat support 10. The fixation point of the lower forceengagement point 51 of the spring element 5 coincides with the lowerbearing point of the front adjustment lever 11. The two force engagementpoints 51 and 52 are arranged so that the spring element 5 runs in aninclined position from the bottom at the front upwards towards the back(in relation to the drive direction of a vehicle) between these twopoints 51 and 52.

[0035] The spring element 5 exerts a force forwards and downwards on theseat support 10 so that the spring force has a component in the loadingdirection G which acts on the seat support 10 or on a person located onthe seat. As such, the seat support 10 is pretensioned by the springelement 5 in the direction of the vehicle floor in addition to beingpretensioned in the loading direction G.

[0036] As a result of the inclined diagonal arrangement of the springelement 5, an increase in the seat height h by swivelling the adjustmentlevers 11 and 12 leads to the two force engagement points 51 and 52 ofthe spring element 5 moving closer together. Any increase in the seatheight h is (as is already described above) accompanied by the seatsupport 10 moving forwards. As a result, the upper force engagementpoint 52 of the spring element 5 provided on the seat support 10 movesnearer in the seat longitudinal direction L to the lower forceengagement point 51, which is locally fixed. With a suitable arrangementof the spring element 5, more particularly its force engagement points51 and 52, this leads to a net reduction in the distance between the twoforce engagement points 51 and 52 despite the increase in the distancebetween the two force engagement points 51 and 52 along the verticalvehicle axis z.

[0037] This means that the spring element 5 in the form of a tensionspring relaxes in the event of an increase in the seat height h by meansof the associated adjusting device. This increase takes place againstthe load G, and releases spring energy (potential energy) to make theincrease in the seat height easier and reduces the amount of forceneeded to be applied by the adjusting device in order to increase theseat height. The spring element 5 thus assists in raising the seatsupport 10 opposite the loading direction G, although it alsopretensions the seat support 10 down in the direction of the load G.

[0038]FIG. 2 shows a modification of the embodiment of FIG. 1 whereby incontrast, the upper force engagement point 52 of the spring element 5does not engage directly on the seat support 10 but rather on aprojection of the rear adjustment lever 13. This rear adjustment lever13 is attached by its upper end on the seat support to pivot about anaxis 13 a and by it lower end to a floor-side structural assembly of thevehicle to pivot about an axis 13 b. The upper force engagement point 52of the spring element 5 thereby coincides with a point 13 c of the rearadjustment lever 13 which, in the event of an increase in the seatheight h relative to the seat support 10, executes a movement with acomponent downwards towards the vehicle floor (i.e. against the upwardpointing vertical vehicle axis z). This leads to an additional reductionin the distance between the two force engagement points 51 and 52 of thespring element 5, and thus to an additional relaxation of the springelement 5. The fixation of the spring element 5 and its force engagementpoint 52 associated with the seat support 10 on a component part (suchas the adjustment lever 13) which in turn is moved during and togetherwith the adjustment of the seat side part 10 (and in addition is movedtowards the other force engagement point 51 of the spring element 5) isparticularly advantageous in the case of vehicle seats which, duringadjustment of the seat height, only execute a slight displacement in theseat longitudinal direction L.

[0039] In the embodiments of FIGS. 3 and 4 the adjusting device for theseat height is shown having a drive device 3 as well as two adjustmentlevers 11 and 13, of a similar embodiment to that shown in FIG. 2. Thedrive device 3 is associated with the rear adjustment lever 13 such thatthe front adjustment lever 11 only serves as a passive compensatinglever.

[0040] The drive device 3 has as a drive an actuating lever 30 (manualdrive) with which a pinion 31, rotatable about an axis 31 a, can beactuated. Teeth of the pinion 31 mesh in a longitudinal spline 33 of atoothed segment lever 32 which is pivotally mounted about an axis 32 a.The longitudinal spline 33 is formed in an elongated recess 32 b of thetoothed segment lever 32. A coupling lever 14 is attached to a bearingsite 34 of the toothed segment lever 32. The coupling lever 14 transfersany movement introduced by the actuating lever 30 through the pinion 31into the toothed segment lever 32 to the rear adjustment lever 13.Depending on the actuating direction of the actuating lever 30, the seatsupport 10 can be selectively raised or lowered. Manual adjustmentdevices of this kind for the seat height are known in the art; as such,further details will not be provided.

[0041] An additional toothed segment lever 35 is mounted with its swivelaxis 35 a on the swivel axis 32 a of the toothed segment lever 32. Thistoothed segment lever 35 has a longitudinal spline 36 in an elongatedrecess 35 b which coincides in geometry and design with the longitudinalspline 33 of the aforementioned toothed segment lever 32.

[0042] In contrast to the first mentioned toothed segment lever 32, theadditional toothed segment lever 35 forms no link in the kinematic chaintransferring an adjusting force exerted by the actuating lever 30through the gearing elements 31 and 32 to the seat side part 10, thecoupling lever 14 and the rear adjustment lever 13.

[0043] The additional toothed segment lever 35 has a bearing point 37for fixing the upper end of a spring element 6 (provided in thisexemplary embodiment by a linear tension spring) by its upper forceengagement point 62. The lower force engagement point 61 of the springelement 6 is fixed on a floor-side structural assembly of the vehicle.In one embodiment this assembly comprises the top rail of a seatlongitudinal guide. The spring element 6 is mounted in the region of therear adjustment lever 13 of the adjusting device for the seat height andserves to remove the backlash from this adjusting device.

[0044] It can be seen from FIGS. 3 and 4 that the additional toothedsegment lever 35 is tensioned by its teeth 36 through the action of thespring element 6 against the teeth of the pinion 31. As such, at leastone toothed element of the pinion 31 located in engagement with theteeth 33 of the toothed segment lever 32 mounted in the kinematic chainis pressed against a toothed flank of the teeth 33. In this manner, theplay is removed from the gearing 31 and the toothed segment lever 32 ofthe drive device 3, and thus the adjusting device for the seat height.The spring 6 thus serves to remove the play from the gearing of thedrive device 3.

[0045] To explain the function of this arrangement, it can be seen froma first arrow RF in FIG. 4 how the additional toothed segment lever 35is stressed under the action of the spring element 36 in the oppositedirection around the axis 35 a from the first toothed segment lever 32under the action of the load G about its identical swivel axis 32 a (seecorresponding arrow R_(B)).

[0046] With a resting seat, torque is introduced through the additionaltoothed segment 35 by means of the spring element 6 into the seatsupport 10 through a brake device, mounted in a manner known to oneskilled in the art between the gearing elements 31 and 32 and the drivelever 30. If torque is applied on the drive side to the actuating lever30 which leads to an increase in the seat height h (see arrow M in FIG.3), then the torque exerted on the pinion 31 by the spring element 6through the additional toothed segment lever 35 assists thecorresponding adjusting movement of the pinion 31 and thus indirectlyalso the elements 32, 14 and 13 on the output side.

[0047] The spring element 6 also serves to tension the support 10 in thedirection of the vehicle floor in order to remove play from the entireadjusting device for the seat height. Furthermore with an increase inthe seat height h, the two force engagement points 61 and 62 of thespring element 6 are moved towards each other so that the spring elementrelaxes and supports the corresponding adjustment movement. The springelement 6 is also made to support the corresponding adjustment movementthrough a diagonal inclined arrangement of the spring element 6 which isfixed by its upper force engagement point 62 on a component part (in oneembodiment the additional toothed segment lever 35) which is connectedto the seat support 10. With an increase in the seat height h in theregion of the bearing point 37 for the upper end of the spring 6, thecomponent part moves down so that the approach movement of the two forceengagement points 61 and 62 towards each other is further assistedduring an increase in the seat height h.

[0048]FIG. 3 shows an alternative embodiment of a spring element 6′which is fixed by a lower force engagement point 61′ on a floor sidestructural assembly of the vehicle and by its upper force engagementpoint 62′ on the previously described bearing point 37 of the additionaltoothed segment lever 35. The spring element 6′ is mounted running alongthe vehicle longitudinal direction L and is only deflected in the regionof its rear spring end by means of a deflection element 65′ so that thisspring end is guided towards the upper force engagement point 62′. Theupper force engagement point 62′ and the deflection element 65′ arearranged so that a straight connecting line (connecting path) extendsbetween the two points 62′ and 65′ inclined to the longitudinaldirection L of the vehicle from the bottom at the front up to the back.

[0049] In order to achieve a particularly sustained tensioning of theseat support 10 for the purpose of reducing the play and assisting theadjusting movement opposite the loading direction G, spring elements 5and 6 can be used at the same time arranged in the region of the frontadjustment lever or the rear adjustment lever of the adjusting devicefor the seat height.

[0050]FIG. 5 shows an alternative to the embodiments of FIGS. 3 and 4whereby the spring element 6 is fixed by its one force engagement point61 on the seat support 10 and by its other force engagement point 62 onthe additional toothed segment lever 35. In this embodiment, the springelement 6 serves only to remove the play from the gearing elements ofthe adjusting height for the seat height, but cannot remove the playfrom the adjusting device overall. One advantage of this embodiment isthat there is no powerful counter effect on the seat overall whereby theassembly of the seat is easier due to the lack of tensioning of theseat.

[0051]FIG. 6 shows diagrammatically a part of the backrest frame 20 ofthe seat frame 1 of FIG. 1, which is mounted pivotally about an axis 21whereby the backrest frame 20 forms a first lever arm 20 a in relationto the swivel axis 21 which supports the back of the vehicle occupant,as well as a second lever arm 20 b.

[0052] A toothed segment 42 is provided in the region of the pivotalaxis 21 on the backrest frame 20. The toothed segment 42 has a toothedspline 43 which meshes with the spline of a pinion 41 which is rotatableabout an axis 41 a. The pinion 41 is rotatable through an associatedmanual or remote-controlled drive and triggers swivel movement of thefirst lever arm 20 a forwards or backwards depending on the direction ofrotation. In an alternative embodiment, the associated drive is anelectric drive.

[0053] In the adjusting region in which the backrest frame 20 is locatedin a useful position in which the backrest frame 20 can support the backof a vehicle occupant located on the seat, the backrest is locatedeither in a perpendicular position (parallel to the vertical vehicleaxis z) or it is inclined backwards. Where the backrest is inclinedbackwards, the load G acting on the backrest frame 20 has the tendencyto intensify the incline of the first lever arm 20 a backwards. Inaddition, the force F_(Lehne) of an occupant located on thecorresponding seat and leaning back against the backrest can still actin the same direction.

[0054] As a result, any adjustment of the incline of the backrest whichmoves it from a rearwardly inclined useful position towards the verticalposition takes place opposite the loading direction G. In order toassist such adjustment of the backrest, a spring element 7 is providedfastened by one lower force engagement point 71 (and thus not on acommon component part which can pivot with the backrest frame 20) and bythe upper force engagement point 72 on a projection 22 of the backrestframe 20 which forms a second lever arm 20 b. The projection 22 forminga second lever arm 20 b is tensioned in the loading direction G throughthis spring element 7 with a defined force F_(Feder) so that the firstlever arm 20 a formed by the backrest frame 20 is biased opposite theloading direction G.

[0055] At the same time the spring element 7, like the correspondingspring elements 5 and 6 in the previous embodiments, serves to reducethe play in the adjusting device for the backrest inclination. Thiscauses among other effects an interaction of the pinion 41 with theteeth 43 of the toothed segment lever 42 which is, as far as ispossible, free of play.

[0056]FIG. 7 shows a modification of the embodiment of FIG. 6 in whichan additional toothed segment lever 45 is mounted to freely pivot aboutthe pivotal axis 21 of the backrest. This toothed segment lever 45 hasan external spline 46 which coincides in geometry and design with theteeth 43 provided on the toothed segment 42 of the backrest frame.

[0057] Using its upper force engagement point 72, the spring element 7engages the additional toothed segment lever 45. The teeth 46 of thetoothed segment lever 45 exert a corresponding moment (which is producedfrom the pretensioning force of the spring element 7 and the distance ofthe force engagement point 72 from the pivotal axis 21 of the backrest)on at least one toothed flank of the drive pinion 41. In this manner,the corresponding toothed element of the drive pinion 42 is made free ofplay and is pressed against the teeth 43 of the toothed segment lever 42provided on the backrest frame 20.

[0058] Furthermore, the moment exerted by the teeth 46 of the additionaltoothed segment lever 45 assists in the rotational movement of thetoothed pinion 41 in a direction which assists displacement of thebackrest opposite the loading direction G, corresponding to anadjustment of the first lever arm of the backrest frame 20 in thedirection of the substantially perpendicular position. The correspondingrotary direction R of the toothed pinion 41 is indicated by an arrow inFIG. 7. Therefore, the additional toothed segment lever 45 acts on thedrive pinion 41 against the action of the load G which engages on thefirst lever arm 20 a of the backrest frame 20; the toothed segment lever45 also acts through its toothed segment lever 42 on the drive pinion41.

1. A motor vehicle seat comprising: at least one adjusting device withwhich a seat part can be adjusted in position with and opposite aloading direction; and at least one spring element which acts underpretension on a kinematic chain of the at least one adjusting devicetransferring the adjusting force; wherein the spring element is arrangedso that it on the one hand serves for reducing a backlash in theadjusting device and on the other hand during adjustment of the seatpart opposite the loading direction it relaxes so that spring energy isfed into the kinematic chain; and wherein during adjustment of the seatpart in the loading direction the spring element is tensioned.
 2. Themotor vehicle seat of claim 1, wherein the spring element exerts a forcewith a component in the loading direction at a force engagement pointwhich is associated with the seat part which is to be adjusted.
 3. Themotor vehicle seat of claim 2, wherein the force engagement point of thespring element which is associated with the seat part which is to beadjusted is moved during adjustment of the seat part opposite theloading direction so that the spring element relaxes.
 4. The motorvehicle seat of claim 3, wherein the spring element serves for reducingthe play of an adjusting device for a height of a seat part which duringadjustment of the height causes a simultaneous displacement of the seatpart in a seat longitudinal direction; and wherein the spring element istensioned between its two force engagement points so that it relaxeswhen the seat part is raised as a result of the simultaneousdisplacement of the seat part in the seat longitudinal direction.
 5. Themotor vehicle seat of claim 4, wherein the spring element is tensionedinclined towards the loading direction.
 6. The motor vehicle seat ofclaim 3, wherein the spring element serves for reducing the play of anadjusting device for an incline of a seat part which is mounted toswivel about an axis whereby adjustable seat part forms in relation tothe swivel axis a first lever arm and the force engagement point of thespring element associated with the seat part engages on a second leverarm of the seat part.
 7. The motor vehicle seat of one of the precedingclaims, wherein the spring element is formed as a tension spring whoseforce engagement points approach one another when adjusting the seatpart opposite the loading direction and move further away from eachother during adjustment of the seat in the loading direction.
 8. Themotor vehicle seat of one of claims 1 to 6, wherein the spring elementis formed as a compression spring whose force engagement points movefurther away from each other during adjustment of the seat part oppositethe loading direction and approach one another when adjusting the seatpart in the loading direction.
 9. The motor vehicle seat of claim 1,wherein all links of the kinematic chain of the adjusting device liebetween the force engagement points of the spring element.
 10. The motorvehicle seat of claim 1, wherein at least one force engagement point ofthe spring element is mounted outside of the kinematic chain of theadjusting device.
 11. The motor vehicle seat of claim 1, wherein oneforce engagement point of the spring element is provided on a componentpart which does not change its spatial position as a result of actuationof the adjusting device.
 12. The motor vehicle seat of claim 11, whereinthe force engagement point is mounted on a top rail of a raillongitudinal guide or a part fixedly connected to the top rail.
 13. Themotor vehicle seat of claim 1, wherein a force engagement point of thespring element is provided on a part which changes its position at thesame time as the adjusting device is actuated.
 14. The motor vehicleseat of claim 13, wherein the force engagement point of the springelement is provided on a link of the kinematic chain.
 15. The motorvehicle seat of claim 14, wherein the force engagement point is mountedon a lever arm or a gearing element of the kinematic chain.
 16. Themotor vehicle seat of claim 1, wherein a force engagement point of thespring element is provided on an additional gearing element which actson an element of the kinematic chain.
 17. The motor vehicle seat ofclaim 16, wherein the additional gearing element acts on a gearingelement of the kinematic chain.
 18. The motor vehicle seat of claim 16or 17, wherein the additional gearing element acts under thepretensioning force of the spring element on the gearing element of thekinematic chain so that movement of the gearing element which leads to adisplacement of the seat part opposite the loading direction isassisted.
 19. The motor vehicle seat of claim 1, wherein the adjustingdevice has an additional gearing element on which the spring elementengages and which is in active connection with a drive element so thatthe spring force counters an output force caused by the weight.
 20. Themotor vehicle seat of claim 16, wherein the additional gearing elementacts under the pretensioning force of the spring element on the gearingelement of the kinematic chain so that the gearing element is tensionedby removing play against another gearing element of the kinematic chain.21. The motor vehicle seat of claim 16, wherein the adjusting device hasa drive pinion whose teeth engage in counter teeth of a gearing elementmounted in the kinematic chain, and that the teeth of the additionalgearing element are designed to agree with the teeth of the gearingelement mounted in the kinematic chain and that the additional gearingelement preferably acts on the drive pinion against the force caused bythe weight action.
 22. The motor vehicle seat of claim 16, wherein agearing element mounted in the kinematic chain and the additionalgearing element are formed as pivotally mounted toothed segment leverswhereby the additional gearing element is mounted freely pivotal on theaxis of the gearing element mounted in the kinematic chain.
 23. Themotor vehicle seat of claim 22, wherein the force engagement point ofthe spring element on the additional gearing element in relation to thepivotal axis of the gearing element mounted in the kinematic chain lieson a side remote from the drive pinion.